Health effects from exposure to PM10

Particulate matter 10 micrometres or less in diameter (PM10) in the air comprises solid particles and liquid droplets from both natural and human-made sources. PM10 is of particular concern because of high concentrations in some areas. It can also damage health, with associated effects ranging from respiratory irritation to cancer. This indicator considers PM10 from human-made sources, such as burning wood or coal for home heating or road motor vehicle emissions.

the number of days when negative health symptoms restricted usual activities, such as work or study (down 9 percent).

These reductions occurred despite an increase of more than 200,000 in New Zealand’s population between 2006 and 2012. The population increase means that the relative reductions are even larger than those in the percentages reported above.

Table 1

Health effects from exposure to human-made PM10, 2006 and 2012

Health effect

2006

2012

Change between best estimates (%)

Best estimate

Low estimate

High estimate

Best estimate

Low estimate

High estimate

Premature deaths(1)

1,170

530

1,600

1,000

460

1,370

-14

Hospital admissions(2)

610

340

980

520

290

830

-15

Restricted activity days(3)

1,490,000

825,000

2,800,000

1,350,000

750,000

2,550,000

-9

1. The best estimate is a 7 percent increase in mortality per 10 μg/m3 of annual average PM10 exposure. The low estimate is 3 percent and the high estimate is 10 percent.
2. The best estimates are a 0.6 percent or 1 percent increase (depending on the cause of hospital admission (cardiac or respiratory)) per 10 μg/m3 of daily average PM10 exposure. The low and high estimates are increases of 0.3 and 0.9 percent, respectively, for cardiac admissions and 0.6 and 1.7 percent, respectively, for respiratory admissions.
3. The best estimate is 0.9 restricted activity days per person, per year, per 10 μg/m3 of annual average PM2.5 exposure. The lower and higher estimates are 0.5 days and 1.7 days per person, per year, respectively.

Note: The health effects from exposure to PM10 are modelled and are determined from the PM10 concentrations the population is exposed to and the estimated health risks experienced at these concentrations. The estimated health risks are determined from national and international epidemiological studies. We presented the number of cases for all three health risks for both 2006 and 2012 and the percentage of change for the best estimates. The best, high, and low estimates reflect only the uncertainty in the health risks of PM10 exposure. The total population estimates at December of that year were 4,185,300 in 2006 and 4,410,700 in 2012.

Source: NIWA

Figure 1

Note: The health effects from exposure to PM10 are modelled and are not determined from hospital records. The estimates are determined from the PM10 concentrations that the population is exposed to and the estimated health risks experienced at these concentrations (7 percent increase in mortality per 10 μg/m3 increase in average PM10 exposure). The estimated health risks are determined from national and international epidemiological studies. The estimated cases per 100,000 people are derived using the population estimate at December (2006: 4,185,300; 2012: 4,410,700).

Figure 2

Note: Figures based on the best-estimated health risk of exposure to PM10 (particulate matter 10 micrometres or less in diameter). The health effects from exposure to PM10 are modelled and are not determined from hospital records. The estimates are determined from the PM10 concentrations that the population is exposed to and the estimated health risks experienced at these concentrations (7 percent increase in mortality per 10 μg/m3 increase in average PM10 exposure). The estimated health risks are determined from national and international epidemiological studies. The estimated cases per 100,000 people are derived using the population estimate at December (2006: 4,185,300; 2012: 4,410,700). PM10 – particulate matter 10 micrometres or less in diameter.

Definition and methodology

We report on the estimated number of premature deaths, hospitalisations, and restricted activity days for the New Zealand population from exposure to particulate matter 10 micrometres or less in diameter (PM10) from human activities.

Premature deaths are deaths, often preventable, that occur before a person reaches the age they were expected to live to.

Hospitalisations relate to hospitalisations for respiratory and cardiac illnesses (not including cases leading to premature death).

Restricted activity days occur when symptoms are sufficient to limit usual activities such as work or study.

We focus on PM10 from human activities because these sources can be managed, unlike particulates from natural sources, such as sea salt.

The health effects from exposure to PM10 are estimated using the Health and Air Pollution in New Zealand model and are not determined from hospital records. The methodology used for these estimates is consistent with international practices and has been internationally and nationally peer reviewed.

The estimates of health effects are determined using the PM10 concentrations that the population is exposed to and the estimated health risks experienced at these concentrations. These health risks are determined from international and national population studies.